1. Field of the Invention
The subject invention relates generally to a device for enabling a low power requirement device to remain operative during a momentary power outage and more specifically to a device for increasing the induced back electrical magnetic field voltage associated with the line voltage connected to an electrical appliance as the line voltage drops off during a momentary power outage to momentarily compensate for the power failure.
2. Discussion of the Prior Art
Digital clocks have been incorporated into many of today's electronic devices. One particular area of electronic devices which digital clocks have been incorporated into is household appliances. Such household appliances include: alarm clocks, radios, televisions, VCR's, microwave ovens, coffee makers, and the like. These digital clocks are operated by direct current at typically very low voltages. However, the power which is supplied to the appliance is generally in the form of high voltage alternating current which must be stepped down to a lower voltage by a transformer and changed into direct current by suitable means such as a rectifier within the appliance to supply voltage to the digital clock.
Momentary power outages have proven to be troublesome for digital clocks. Unlike analog clocks which are driven by line power and which re-start when line power is restored after a momentary power outage, digital clocks do not restart after a momentary power outage. Generally, digital clocks, after a momentary power outage, are programmed to go into a pre-designed mode so as to indicate that a power interruption has occurred. For example, after a momentary power outage, a digital clock may be designed so as to continuously flash "12:00", until such a time as the user resets the digital clock.
Many of today's households have numerous digital clocks, and the failure and subsequent resetting of each individual digital clock after a momentary power outage is a tedious and burdensome task. Moreover, the failure of digital clocks after a momentary power outage may give rise to undesirable situations. For example, if an alarm clock utilizes a digital clock, a momentary power outage could cause the user to oversleep and not wake at the proper time. Further, the failure of a VCR digital clock after a momentary power outage may result in the failure of the VCR device to record preselected programs.
Momentary power outages can be attributed to numerous causes which generally include interruptions in the distribution of line power caused by acts of God, and or, acts of man. The vast majority of momentary power outages last for a duration of less than one second, however, such a duration is sufficient to give rise to the failure of digital clocks.
There have been many prior attempts to provide for backup power which is to be utilized in the event of a momentary power outage. See for example, U.S. Pat. No. 5,138,185 to Weinstock, No. 5,057,697 to Hammond et al., and No. 5,001,623 to Magid. Such devices essentially utilize battery means for supplementing electrical power to an electrical device in the event of a momentary power outage. However, the usage of batteries for supplying a source of backup power is disadvantageous in that batteries often need replacement or require carefully monitored charging. If a faulty battery is not replaced of if a battery is not charged to a threshold voltage level, this battery may be unable to provide an amount of electrical power sufficient to maintain a digital clock in an operating state in the event of a momentary power outage. Moreover, if the battery is to be incorporated directly into the appliance, the battery is further disadvantageous in that it requires a large storage space in the appliance.
Accordingly, it is an object of the present invention to provide an improved backup power device to keep low power requirement electrical devices in their operative state for at least a period of time greater than the temporal extent of an average momentary power outage.
Yet another object of the present invention is to provide a portable and inexpensive device which prevents digital clocks from resetting in the event of a momentary power outage.
Other objects, advantages and new features of the present invention will become more readily apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.